An exhaust bypass valve is often used to control operation of serial turbocharger systems. Such a valve may be operated to physically divert exhaust or alter pressures in exhaust pathways, for example, to direct exhaust flow partially or fully to one of multiple turbines in a system. During operation, a typical exhaust bypass valve experiences high exhaust pressure on one side and lower pressure on the other side. To effectively seal the high pressure environment from the low pressure environment, considerable force is required to maintain contact between a valve and a valve seat. Conventional efforts to provide a robust seal have proven costly and even to deteriorate over time (e.g., due to valve seat oxidation). Various technologies described herein have potential to reduce cost as well as provide for effective exhaust bypass valve sealing.